Container treatment plants often include filling machines, labeling machines, inspection machines or rinsers. The containers are usually bottles for liquids, such as drinks. The bottles can be made of a transparent or translucent material, for example, glass or a translucent plastic, such as PET. It is also feasible for the containers to be made of other materials and filled with other contents.
Bottles must sometimes be securely gripped. In one example, a gripping-and-holding device on a rotor has pivotably mounted gripper arms on a support plate. A spring located opposite the gripper cheeks forces these gripper arms into closed position. Slanted inlets on the front sides of the gripper arms permit bottles to be pushed in or pulled out by compressing the spring.
Another known gripping-and-holding device has a securing element between bearing ends of gripper arms. Each bearing end has an edge recess. Twisting the gripper arms into an extreme open position and carrying out a prior tension-release of the spring releases the gripper arms. This enables them to be removed easily and without tools. The support body has deformable mounting tabs made of an elastic material. These effect a clamping position on securing elements of the transport element. The securing elements have flat-plate heads or washers that prevent the deformable mounting tabs from falling out.
A traction spring that has been secured on securing elements on the gripper arms provides the closing force of the gripper arms. Pressing a bottle into the holder of the gripper arms opens the arms and causes the traction spring to develop a closing force. Sometimes, the spring is not strong enough and gripper arms come loose from their closed position. This can result in losing the bottle that was being held by the gripper arms. This disrupts plant operation.